The invention relates to a quarter turn thermostatic cartridge with concentric controls, and ceramic discs as well as a mixer tap including such a cartridge.
Most quarter turn taps with ceramic disc cartridges which are currently used on sinks or washbasins, do not allow the temperature of the outlet fluid the xe2x80x9cmixedxe2x80x9d or xe2x80x9clukewarmxe2x80x9d fluid to be efficiently stabilised, when the pressure and/or the temperature of one of the inlet fluids (the xe2x80x9ccold fluidxe2x80x9d and xe2x80x9chot fluidxe2x80x9d) varies.
Cartridges of this type, equipped with a thermostatic element to regulate the temperature of the outlet water, have, therefore, been created.
Mono control thermostatic cartridges of this type are well known, allowing for xe2x80x9cmixerxe2x80x9d taps, that is to say whereby the regulation of the flow and the temperature are carried out by the operation of a single lever. These cartridges ensure the regulation of the flow by means of two superimposed ceramic discs, the lower disc comprising channels for the rise and fall of the inlet cold fluid and hot fluid, and the regulation of the temperature of the mixed outlet water by means of a temperature regulating valve situated downstream, underneath the lower disc, joined to a thermostatic control element.
Thermostatic cartridges of this type with concentric controls are also known, requiring a tap comprising two concentric handles for the control of the flow and temperature. Flow regulation is also provided by two ceramic discs and temperature regulation by a temperature regulating valve joined to a thermostatic element, but the two discs comprise channels for the rise and fall of the cold fluid and of the hot fluid, and the valve, situated downstream from the channels, is arranged, this time, on top of the upper disc.
In both cases, the arrangement of the cartridge limits the diameter available for the temperature regulating valve and the section for the flow of fluid, resulting in poor temperature control, which is incompatible with current standards for thermostatic taps, and a weak flow, which limits the range of possible applications.
The aim of the invention is to overcome these drawbacks and, to this end, relates to a thermostatic cartridge with ceramic discs and concentric controls for a quarter turn fluid tap, comprising a regulating valve connected to a movable portion of a thermostatic element, and a first and second disc for regulating the flow, coupled on one of their faces, in which the first disc has two internal transverse hot fluid passages extending approximately in circumferential arcs of approximately equal radiuses, separate and approximately end to end, two internal transverse cold fluid passages extending approximately in circumferential arcs of approximately equal radiuses, separate and approximately end to end, and an internal groove opening onto the face of the disc which is not coupled to the second disc and the base of which forms a seat for the valve and is in communication with one of the cold fluid passages, and the second disc has two internal transverse passages of hot fluid and cold fluid respectively, extending approximately in circumferential arcs and rotatable relative to the first disc between an open position, in which the hot fluid passage of the second disc links the hot fluid passages of the first disc, and the cold fluid passage of the second disc links the cold fluid passages of the first disc, and a closed position when the hot fluid passage of the second disc is isolated from at least one of the hot fluid passages of the first disc and the cold fluid passage of the second disc is isolated from at least one of the cold fluid passages of the first disc, and vice versa.
Thanks to this arrangement, efficient temperature regulation is achieved in a large range of flows, and particularly for very strong flows.
In addition, the cartridge may also have one or more of the following further characteristics:
the respective hot fluid and cold fluid passages of the second disc are transverse passages, and the cartridge includes a flow control lever provided with two chambers for hot fluid and cold fluid respectively, opposite the respective hot fluid and cold fluid passages of the second disc; thus, the hot and cold fluid flow sections between the respective hot fluid and cold fluid passages may be large while not requiring a large thickness for the second disc.
the respective hot fluid and cold fluid passages of the second disc do not cross this disc from one side to the other; in this case the manufacture of the second disc and of the control handle is simplified, as is the assembly of the cartridge.
it includes an annular space for hot fluid, extending around the valve and defined by the exterior surfaces of the valve and the internal surfaces of a device comprising a valve seat and/or a casing in which the valve and the discs are housed; this provides for distribution of the hot fluid around the valve, which contributes to stable regulation.
it includes an annular space for cold fluid, extending around the valve and defined by the exterior surfaces of the valve and the internal surfaces of a device comprising a valve seat; this provides for distribution of the cold fluid around the valve, which also contributes to stable regulation.
it comprises a casing having an integral hot fluid inlet pipe and a cold fluid inlet pipe communicating respectively with a hot fluid passage and a cold fluid passage of the first disc which is rotatable with the said casing, a hot fluid return pipe into which runs a hot fluid return passage of the first disc, a surface forming a seat for the valve and defining with the valve a passage for the hot fluid coming from the first disc through the hot fluid return pipe to direct it towards the interior of the valve, and an internal guiding surface of the valve, and the casing contains the two discs as well as the regulating valve and the thermostatic element, supported by a casing plug; thus the manufacturing costs of the cartridge remain relatively low; and
it comprises a device for creating agitation, having an irregularly shaped internal surface, opposite a thermo-sensitive area of a thermostatic element; thus thermostatic regulation is improved.
The invention also relates to a mixer tap provided with a cartridge as described above, and including a flow control device connected to a flow control lever of the cartridge, and a temperature control device connected to a temperature control lever of the cartridge.